02-band-limited-oscs.py - Oscillators whose spectrum is kept under the Nyquist frequency.¶
This tutorial presents an object (misnamed LFO but it’s too late to change its name!) that implements various band-limited waveforms. A band-limited signal is a signal that none of its partials exceeds the nyquist frequency (sr/2).
The LFO object, despite its name, can be use as a standard oscillator, with very high fundamental frequencies. At lower frequencies (below 20 Hz) this object will give a true LFO with various shapes.
The “type” slider in the controller window lets choose between these particular waveforms:
Saw up (default)
Sample and hold
from pyo import * s = Server().boot() # Sets fundamental frequency. freq = 187.5 # LFO applied to the `sharp` attribute lfo = Sine(0.2, mul=0.5, add=0.5) # Various band-limited waveforms osc = LFO(freq=freq, sharp=lfo, mul=0.4).out() osc.ctrl() # Displays the waveform sc = Scope(osc) # Displays the spectrum contents sp = Spectrum(osc) s.gui(locals())